Despite spending $12 billion annually on the emergency evaluation of chest pain in the US, only 15% of admitted patients have a cardiac cause of their presenting symptoms. Clinical decision units (CDUs) improve resource utilization and are a recommended care option by the American College of Cardiology / American Heart Association, but are underutilized in non-low risk chest pain patients due to weaknesses of traditional cardiac testing. Cardiac magnetic resonance imaging (CMR) is sensitive and specific for ischemia, can simultaneously assess cardiac function and myocardial perfusion, and could revolutionize the diagnostic process for intermediate risk patients with chest pain. The superior accuracy of CMR could decrease testing and invasive procedures. The high sensitivity for ongoing ischemia could allow imaging in parallel with cardiac markers. As a result, CMR could improve the care of ED patients with intermediate risk chest pain. However, the efficiency and safety of CMR has not been extensively tested in the CDU setting. Objectives: The long term objective of this research direction is to conduct a multi-center efficacy and safety trial of a CDU-CMR strategy. Prior to this, measuring the impact of a CDU-CMR strategy on efficiency and safety in a single center setting is required to determine whether a large multi-center trial should be conducted. Accordingly, this application has the following specific aims: SA1. Compare among a CDU-CMR strategy and an inpatient care strategy the occurrence of the composite of revascularization, re-hospitalization, and recurrent cardiac testing through 90 days. SA2. Compare index hospitalization length of stay between a CDU-CMR strategy and an inpatient care strategy. SA3. Monitor the occurrence of the following safety events through 90 days by group: a. Acute coronary syndrome b. Mortality c. Stress testing-related adverse events Methods: Participants (n=146) at intermediate risk for ACS will be recruited into a clinical trial from Wake Forest University Baptist Medical Center (WFUBMC) ED. Participants will be equally randomized to CDU-CMR or inpatient care. CDU-CMR participants will undergo resting and stress CMR imaging in parallel with serial cardiac markers. Inpatient care participants will undergo serial cardiac markers followed by existing cardiac testing as determined by their care providers. The primary outcome is the composite of 90 day revascularization, re-hospitalization, and recurrent cardiac testing. The secondary outcome is include index hospitalization length of stay. Safety events include ACS after discharge, mortality, and stress testing-related adverse events. PUBLIC HEALTH RELEVANCE: The US health care system cannot afford to continue lengthy inpatient evaluations for patients with chest pain. This investigation will determine if a cardiac MRI strategy in a clinical decision unit is more efficient at delivering care to patients with chest pain than an inpatient care strategy. Because of the large number of patients evaluated for chest pain in the US, improvements in the care processes for these patients will have a large positive societal impact.